The present invention relates generally to the field of electrical contactors, circuit interrupters, circuit breakers, and similar devices. More particularly, the invention relates to a gas diverter used to slow, cool, and divert hot gas generated during the operation of electrical switching devices.
A variety of electrical switching devices are known and commercially available for establishing and interrupting current carrying paths between an electrical energy source and an electrical load. Electromechanical switchgear, for instance, is known for both single-phase and multiple-phase circuits. Such equipment generally includes an actuating assembly mechanically connected to a switch or contactor structure. In remotely-controllable switchgear of this type, it is commonplace to provide an electromagnetic actuating assembly which operates either on alternating current or direct current. The actuating assembly is energized by a control signal, such as from a remote controller. Electrical current through the actuating assembly causes movement of an armature under the influence of an electromagnetic field generated by an actuating coil. A carrier coupled to the armature, moves the movable contacts to either open or close the current-carrying path through the device. Depending upon whether the device is configured to be normally-open or normally-closed, the armature either separates the moveable contacts from the stationary contacts or brings the contacts together when the control signal is applied.
In industrial contactors of the type described above, the elements of the contact assembly may be subjected to a number of opening and closing cycles. During each operating cycle, arcs are produced between the movable contacts and the stationary contacts. In high power applications, the arcs produced generate a significant amount of electrical energy which is thereby converted into thermal energy. It is during this conversion process that the relatively non-conductive ambient atmosphere confined inside the switching device undergoes ionization and becomes a highly conductive hot gas and plasma.
The hot gas and plasma is generally permitted to escape from switchgear though splitter plates and holes in the device housing. Concerns in such situations include potential phase-to-phase short circuits in multi-phase devices, and the release of hot gases. The ionized gas that may exit the devices is generally conductive and could lead to short circuits if similar ionized gas exits from neighboring phase sections of the devices. The diffuse nature of the gas and plasma allow it to flow in a variety of directions providing for a vast number of possible short circuit paths. Certain devices include short dividers coupled to the outer surface of the housing intended to separate ionized and hot gases. However, these do not generally divert or cool the gas.
There is a need, therefore, for improved switching devices and structures associated with such devices. In particular, there is a need for improved techniques for directing and cooling hot gases and plasma created during opening or closing of contacts in such devices.